value quality siderealorsynodic author ref method 17.8900 2+ Synodic Ryan 2017AJ....153..116R Lightcurve 17.9020 2 Synodic Szabo 2017A&A...599A..44S Lightcurve 17.9045 2 Sidereal Durech 2023A&A...675A..24D Model